Your opinion is actually quite sensible and not as unpopular as you might think. Pronouncing foreign words as they are intended in their original language shows respect for the culture and can improve your own listening comprehension and accent. The backlash often comes from listeners who feel insecure about their own pronunciation or who mistakenly equate accuracy with showing off.
That said, there are honest tradeoffs to consider. If you pronounce every foreign word perfectly while speaking English, you may create a jarring contrast that disrupts conversation flow for monolingual listeners. For example, saying "croissant" with a flawless French uvular R in an otherwise English sentence can sound affected, not because the pronunciation is wrong, but because it breaks the phonetic consistency of the sentence. The key is context: in a language learning setting or among multilingual friends, authentic pronunciation is a plus. In a casual chat with people who don't speak the source language, a slightly anglicized version may be more natural.
Another nuance is that some words have already been fully adopted into English with standard anglicized pronunciations (like "karaoke" or "tortilla"). For these, using the original pronunciation is fine, but insisting on it can come across as pedantic. The real problem isn't the pronunciation itself but the attitude behind it. If you correct others or make them feel bad for saying "croissant" with an English R, that's where obnoxiousness starts.
Your best next step is to practice situational awareness. When speaking English, use authentic pronunciation for loanwords only if it flows naturally and doesn't distract from your message. When learning Dutch, for example, you should absolutely aim for accurate pronunciation of Dutch words like "Gouda" or "Scheveningen" because that directly supports your learning goals. The rule of thumb: prioritize clarity and connection over perfection. If your listener understands you and you're not being condescending, you're doing it right.